Israel allowed 40 Palestinians from the Gaza Strip to visit relatives held in Israeli jails on Monday, the first such visits in five years, implementing a deal reached in May that ended a prisoners' hunger strike, families and officials said.

"Forty people - families of 24 prisoners - arrived a short while ago at the Ramon prison," a Prisons Service spokeswoman said, adding that visits from prisoners' relatives in Gaza would now be held on a weekly basis.

Israel banned family visits to prisoners from Gaza in 2007, a few months after Palestinian militants abducted Israeli soldier Gilad Shalit, holding him captive until they exchanged him for 1,000 Palestinian prisoners in an Egyptian-mediated deal in 2011.

Israel also cut off Gaza prisoners' supplies of educational materials and limited their access to television.

Monday's visits were part of a new agreement reached earlier this year to end a month-long hunger strike by some 1,600 Palestinian prisoners demanding better detention conditions.

The hunger strikers' demands included the resumption of family visits and the ending of Israel's policy of detaining some terrorism suspects without trial - a policy that applies to about 320 of the 4,800 Palestinians in Israeli jails.

The prisoners ended their fast in May after Egypt mediated a deal by which Israel gave in to some demands but did not promise to end its "administrative detention" without trial, citing security concerns and the need to protect secret informants.

Abdallah Qandil, spokesman of a prisoner association in Gaza, accused Israel of violating the May agreement, saying the first visits had not been arranged soon enough, had not included enough families and were still subject to serious restrictions.

Sabah al-Jerjawi and her husband were among those who passed a sleepless night in Gaza, waiting for the bus organised by the International Committee of the Red Cross to take them to their jailed kin in Israel.

Clutching a modest lunch in a black plastic bag for the long trip ahead, she said her son was never sentenced but had been in an Israeli prison for 14 months. Though delighted to be able to visit him, she was frustrated by the restrictions imposed by the Israeli authorities.

"He asked for training suits and bedding. Many people prepared many kinds of things when they heard about the visit, but the Israelis spoiled their happiness by telling us all we could take with us was a bottle of water and a sandwich," she said.

"Our joy will be complete when all families get to visit their sons."

The round trip from Gaza to Ramon prison in the parched Negev desert could take up to 14 hours, and relatives will be allowed to see the prisoners for just 60 minutes, Qandil said, adding that children were banned and gifts forbidden.

ICRC officials, who help facilitate the visits, urged that all Gaza prisoners in Israeli jails be granted family visits. There are 554 men in Israeli prisons whose families are from the Gaza Strip, according to an ICRC statement.

"We have repeatedly called for the resumption of family visits, which are a lifeline for detainees and their families. Under international humanitarian law, Israeli authorities have an obligation to allow the detainees to receive family visits." said Juan Pedro Schaerer, the head of the ICRC delegation in Israel and the occupied territories.

A few prisoners were still on hunger strike to back demands for their early release, among them Akram Al-Rekhawi, a member of the Islamist group Hamas who has served eight years of a nine-year sentence and has been on intermittent hunger strike for 94 days.